1. Technical Field
The invention relates to truck caps, and in particular to an outer shell in combination with an internal rigid frame and an exterior mounting rack able to support heavy loads. Even more particularly, the invention relates to such a truck cap in which the weight of the heavy load that is supported on an external rack is supported by the truck body through the internal frame concealed within the cap shell.
2. Background Information
A considerable number of pickup-type trucks are used by individuals for many types of business activities or just as a personal vehicle. These pickup trucks have an open rear bed or cargo area which is exposed to the weather. Various types of enclosures are used to protect this cargo area from the weather and to secure cargo, tools, etc. stored in the rear area from theft. These enclosures are referred to as a shell, canopy, topper, bed cap, box cap etc. and come in numerous configurations and sizes. These enclosures are usually attached to and supported by the side rails or frame of the truck body which form two sides of the open cargo area. Many of these enclosures are made of fiberglass, aluminum, wood etc., with fiberglass being the most common.
Many of these pickup trucks are used in various industries and hold various types of tools and other equipment for use on a job site. However, due to the construction of the enclosure, usually of a lightweight material such as fiberglass, they are not able to support appreciable weight, even though it is desirable to mount ladders and other equipment on top of the enclosure. In order to be able to accommodate greater loads, the enclosure must be made of a more rigid material with internal reinforcing, which adds appreciable to the weight, size, and cost for the truck enclosure or have a type of support frame which extends externally about the weather-proof shell such as shown in U.S. Pat. No. 8,087,716. Although some of these prior art reinforced caps and external frames enable the external load to be heavier than heretofore possible, they increase the cost of the truck enclosure, increase the external size of the vehicle cap and detract from the appearance thereof.
Therefore, there is a need for an improved truck enclosure or cap for the rear cargo area which is able to support greater loads externally of the enclosure adjacent the top thereof without detracting from the appearance of the vehicle while still providing weather-proof protection for the heretofore open truck bed or cargo area.